There are numerous applications requiring a scanning type radar system. Conventionally such scanning has been done in one of two ways. In the first way, the radar antenna may be adapted to move or pivot in a manner such as to achieve the necessary scanning. Since the antenna must be connected to the rest of the radar by a mechanical waveguide structure, a piece of articulating waveguide must be used, which is costly and periodically requires repair. Further, the waveguide "leaks" so not all energy in the waveguide produced by the radar is transmitted by the antenna and not all the return energy received at the antenna is transferred to the radar electronics. The other way of achieving antenna scanning is by the use of a phased array antenna in which the scanning occurs by electronic means. No physical movement of the antenna in a phased array radar is necessary. Phased array radar antennas, however, are very costly. Furthermore, with either scanning method, a structure positioned between the antenna and object or surface to be scanned undesirably blocks the microwave beam between the radar antenna and object.